The present invention relates to apparatus facilitating the connection of conduit segments. In particular, it relates to apparatus that facilitates the completion of flange-type connections between conduit segments.
The laying of pipelines or other conduits in submerged locations can be a difficult and time consuming task, especially where the conduits are large (and thus heavy). It is often virtually impossible for divers to manually align the flanges and achieve a desirable joint therebetween. Submerged power apparatus is essentially unavailable and would be prohibitive in cost. Supporting and moving the conduit segments employing power apparatus on the surface (e.g., a crane supported on a barge) is quite difficult in view of the relatively fine adjustments in conduit position or orientation that may be required during a coupling operation.
There is thus a need, and a need that is growing as the requirements for submerged conduits grows, for an effective flange alignment system and technique that is relatively simple and efficient to employ even in the difficult conditions under which the divers must work (e.g., difficulty of applying large manual forces).
Naturally, there have been many previous proposals for apparatus to facilitate the coupling of conduits. One common technique involves the use of a cradle to support the opposed conduit ends during, and even after, the coupling operation. Examples of this type of arrangement can be found in Roberts U.S. Pat. No. 1,869,778 and in Lochridge U.S. Pat. No. 3,603,617, the latter assigned to the assignee of the present invention. Such systems, however, require a relatively firm bed for the cradle to rest upon to order to be successfully employed; are often not reusable (e.g., the cradle often remains permanently in place beneath the pipes even after completion of the coupling); and typically have no provision for the simple and effective adjustment of orientation of one conduit relative to the other to achieve the precise alignment necessary for proper coupling.
Another arrangment for dealing with the problem of submerged coupling of heavy conduits is exemplified by Robley U.S. Pat. No. 3,267,682 and by Burrows U.S. Pat. No. 1,874,081. Each of these teaches the use of a crane supported on a barge on the surface of the body of water, the crane being used to lower a large frame that carries a conduit segment to the bed of the body of water for placement adjacent an existing conduit segment. Once the new segment is lowered in place, divers complete the connection after the conduit has been manipulated to precise alignment with the existing conduit segment by either maneuvering of the remote crane or a power system for moving the new conduit segment internally in the submerged frame (e.g., see Robley U.S. Pat. No. 3,267,682). Such proposals, of course, require expensive, sophisticated equipment.